SW 439 doubling

R

Ronnie

New member
I recently acquired a S&W 439 that is double firing. Anyone have any ideas what might cause this?? I'm thinking along the lines of a firing pin spring and/or a sear spring.
When I got the pistol I did a quick clean on it. Took it out and fired it, and shot 7 rounds in 4 shots..put 2 more in a mag and it shot those in 1 shot.
I semi-disassembled the pistol and the firing pin channel was full of crud and somewhat wet. Cleaned and dried it, took it back out and fired it again 5 mags and it doubled twice.
I would really like to fix this myself "if" possible, I live in a small town and finding a good pistol smith would be hard.
Thanks..Ronnie
 
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Hard to diagnose without seeing the gun, but I suspect a too light trigger pull is resulting in your own finger doing the doubling. A previous owner might have decided to do a "trigger job", got it too light, then sold off the gun rather than put money into fixing it. Whether the problem is the sear, the sear spring, the hammer, or something else, I wouldn't be able to tell long distance. Parts are available from www.gunpartscorp.com if you can figure out the problem and need them.

Jim
 
I did notice thait has a very light tigger pull. What could I look to see if it has had a trigger job performed?
Thanks..Ronnie
 
Send the gun to a professional gun smith and have it fixed right. That trigger is dangerous, and you need to have it worked on by a pro. Personally, I'd call Smith & Wesson and sent it to them.

I know it'll be a pain, but it is better than messing with it yourself.
 
I will second the idea of sending it to S&W. I don't know if you can tell or not what has been worked on. In fact, it probably is not a good idea to take that gun down unless you are fairly familiar with S&W autos, as they can be a pain to put back together.

Call S&W and they will likely send a shipping label so they pay shipping both ways. Their customer service is very good; the cost, if any, will be well worth it as the gun is dangerous as it is now.

Jim
 
+1 on Jim Keenan's advice. Reassembling my Model 39's or my 3914 is a classic case of needing 3 hands.

It could be a sear or the drawbar that does not have sufficient mating surfaces. The hammer notches could be worn if the gun has been fired extensively (but I doubt this).

See the 439 diagram here.

The trigger drawbar is #9, the sear is part #61. A worn disconnector (#8) could also cause the gun to double (if it's really worn or malfunctioning, the gun could run until empty!)

Pop the grips off your gun and examine the drawbar and sear engagements with a good light. The engagement surfaces are usually shiny on blued steel. If you see other signs of filing, honing or bluing removal, someone might have tried a trigger job and botched it.

In any event, S&W should be able to diagnose and repair your 439. I'd suggest having them diagnose it and replace the springs while it's in the shop.
 
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